The poultry industry hatches more than 9.1 billion birds each year in the United States. The intense genetic selection of turkeys, chickens and other poultry for increased body size and growth rates has achieved dramatic results. However, this genetic selection has adversely affected the efficiency of poultry production by causing low average hatchability rates for the eggs, as low as about 70% for many strains of domestic turkeys (Christensen, U.S. Pat. No. 4,604,968). Since the intense genetic selection of poultry continues today, and will continue for the foreseeable future, it is possible that hatchability rates will continue to decrease. Efforts to increase the hatchability of poultry eggs have included optimizing the environmental conditions during egg incubation, and the injection of antibiotics into eggs to control disease.
The ability of a developing embryo to breath during the incubation process occurs solely by the diffusion of gases through the shell (Christensen and Bagley, Poultry Sci., 63, 1350-1356 (1984)). During incubation, an egg must lose a certain amount of its weight, mainly by the loss of water (Peebles et al., Poultry Sci., 66, 834-840 (1987)). The rate of water loss from an egg can influence the rate of embryonic development, pre-pipping oxygen consumption rate, metabolic rate, and gas exchange. The effect of modifications of the egg shell on hatchabililty has been studied, typically by dipping eggs in a solution including sodium hypochlorite (Christensen and Bagley, Poultry Sci., 63, 1350-1356 (1984), (Peebles et al., Poultry Sci., 66, 834-840 (1987), Bagley and Christensen, Poultry Sci., 70, 1412-1418 (1991)). The poultry industry has a continuing need to increase the hatchability of eggs.